1. Field of the Invention
The disclosed invention relates generally to a means of generating useable electrical energy by ultimately employing the energy of moving waves on the surface of an open body of water.
2. Description of the Related Art
Several means have been invented for the purpose of converting wave energy into electrical energy, and these seem to fall into the following broad categories:
A. Devices which directly, or at least early in the process, convert the oscillating motion of the waves into rotational energy, which is then generally used to directly turn a generator. Examples of this category of inventions include: Shoreline installations, such asxe2x80x94Kumbatovic (U.S. Pat. No. 5,789,826, Aug. 4, 1998), which employs a flexible boom system to place a moveable turbine into the most active focal wave zone; or Brown (U.S. Pat. No. 5,808,368, Sep. 15, 1998), which places floats at the end of long shore-based lever arms that pivot in response to the vertical motion of the floats in the waves; or
Buonome (U.S. Pat. No. 4,454,429, Jun. 12, 1984), which imposes a series of constrictions upon near-shore waters (which serve to amplify the wave action), and places floats between the constrictions, with lever arms on the shore in a manner reminiscent of Brown; or
Hidenori, et. al. (U.S. Pat. No. 5,027,000, Jun. 25, 1991), which uses the, rising and falling of water in open-bottomed cylinders placed near shore to mildly compress large volumes of air and drive an air turbine; or
Boyce (U.S. Pat. No. 4,748,338, May. 31, 1988) which utilizes a pontoon raft and a pyramidal framework to support a large pendulum, which oscillates as the raft tilts in the waves, ratcheting a drive shaft;
xe2x80x94and: Near shore installations with foundations on the shore bottom, such asxe2x80x94
Eberla (U.S. Pat. No. 5,986,349, May. 18, 1998; U.S. Pat. No. 4,206,601, Jun. 10, 1980), which utilizes a vertical pilaster and a toroidal float surrounding the pilaster to pressurize air or a fluid as the float moves up and down relative to the pilaster; or
Youngblood (U.S. Pat. No. 5,359,229, Oct. 25, 1994), which employs a spherical float telescopically mounted to a secured vertical column, with a chain and counterweight, which turn a drive shaft as the float bobs; or
Borgren (U.S. Pat. No. 4,241,579, Dec. 30, 1980), wherein a central support grounded on the ocean floor supports a multiplicity of shafts on which are anchored floats that engage the shaft while bobbing, thereby translating the energy to rotational energy; or
Whitticar (U.S. Pat. No. 4,560,884, Dec. 24, 1985), which posits a stationary platform with a float connected to an air compressor, that delivers compressed air while bobbing;
xe2x80x94and: Open ocean craft, platforms, or largely submerged devices (that also could be located near-shore if desired, or that do not specify a location), such asxe2x80x94
Russo (U.S. Pat. No. 4,803,839, Feb. 14, 1989), which mounts a float on a raft and achieves a certain amount of bobbing motion of the float relative to the raft, and mechanically converts this to rotational energy, driving a generator; or
Lamberti (U.S. Pat. No. 4,389,843, Jun. 26, 1983), which mounts floats on pivot arms from a boat, and using drive sprockets, gears, and clutches, converts this likewise to rotational motion in a generator; or
Trepl and Bashardoust (U.S. Pat. No. 5,424,582, Jun. 13, 1995), which utilizes floats of different design and weight (to be responsive to both rising and falling phases of the wave) to drive a xe2x80x9cconstant speedxe2x80x9d flywheel via mechanical linkages; or
Sieber (U.S. Pat. No. 5,394,695, Mar. 17, 1995), which posits an array of floats attached to piston-type pressurization units, connected in series to serially compress a fluid (gas or liquid) to a high pressure to then drive turbines and generators; or
Hyun (U.S. Pat. No. 5,854,516, Dec. 29, 1998) which employs a multiplicity of buoys suspended in an array in the ocean, where the bobbing motion of the buoys is converted to rotational energy, driving a liquid compression unit, and using the pressurized liquid to drive a turbine and generator; or
Gordon (U.S. Pat. No. 4,781,023, Nov. 1, 1988), which employs a floating array of hinged floats whose motion relative to their support arms, or to their multiple segments, can drive a piston-type pressurizing device, producing xe2x80x9cmechanical, hydraulic, or electrical powerxe2x80x9d; or
Tateishi (U.S. Pat. No. 5,889,336, Mar. 30, 1999), which utilizes a float and a dead weight attached via a chain to convert to rotary motion, driving a generator; or
Shim (U.S. Pat. No. 5,066,867, Nov 19, 1991), which uses ropes and gears attached to an array of bobbing floats to convert to rotational energy; or
Windle (U.S. Pat. No. 4,754,157, Oct. 10, 1986) which employs a wave-actuated spring-loaded (or weight/tether) mechanism to drive a hydraulic pressurization device, yielding pressurized water to operate a hydraulic generator.
Most of the purely mechanical transducing devices suffer the limitation of unregulated rotational speed of the generator, rendering the output suitable only for non-critical current applications (usually the charging of batteries). To invert such output to a form suitable for the power grid requires an additional, inefficient step, rendering most of these devices impractical. Those that govern the rotational speed employing some kind of load control simply waste any energy produced in excess of the governed speed, again rendering them somewhat impractical.
The shoreline devices, additionally, are generally massive and ugly, and tend to disrupt the shoreline environment; and the near-shore inventions also pose some such additional visual and environmental problems.
The open ocean inventions that are boat-, raft-, or float-based will tend to dampen the surface waves because of their mass (as will those devices with large storage or generating facilities at or near the surface).
Those inventions that posit floats that are specially-designed or weighted, hinged, or otherwise encumbered are needlessly elaborate and generally more expensive than the within invention. In trying to optimize certain aspects of wave energy collection, their overall practicality is called into question. The floats of the within invention are simple, affordable, and responsive, being somewhat small relative to the wavelength of the average wave, and the overall simplicity of each power-producing module (if assembled into multiple arrays) allows easy maintenance, or module replacement, without taking the entire system down.
B. xe2x80x9cOtherxe2x80x9d devices, which variously:
use a pressure transducer on a surface below sea level to directly convert to electrical energy, which, again is DC in nature and must be inverted to be applied to the power grid; and pressure transducers have expense considerations inherent within them as well (such as North, U.S. Pat. No. 5,955,790, Mar. 13, 1998);
collect ocean streaming energy, which is used to drive a turbine; but this suffers from uneven speed of flow (Williams, U.S. Pat. No. 5,592,816, Jan. 14, 1997);
contain a xe2x80x9cslider xe2x80x9d or other mass, on floating rails or in a floating cylinder, that moves back and forth when its support tips due to wave motion, and interacts with some means of pressurizing a fluid or driving a mechanism, a device which seems to suffer from frictional and inertial dissipation (such as Rubi, U.S. Pat. No. 4,851,704, Jul. 25, 1989 or Stupakis, U.S. Pat. No. 4,843,250, Jun. 27, 1989);
utilize wave action to move a permanent magnet past a coil and induce electrical current, which again would be sporadic in nature and suitable only for charging batteries or other electrical storage devices (as in Neuenschwander, U.S. Pat. No. 4,539,485, Sep. 3, 1985);
employ a xe2x80x9cliquid flywheelxe2x80x9d, or whirling vortex of water yielded from waves passing through a refractive horn and ramp, which drives a turbine; and again may produce energy in a pulsatile fashion (as in Wirt, U.S. Pat. No. 4,152,895, May. 8, 1979).
A major aspect of the disclosed invention (the xe2x80x9cmodular power-producing networkxe2x80x9d, or xe2x80x9cpower netxe2x80x9d) is that it provides an efficient means of converting oscillatory ocean wave motion into governed alternating current suitable for connection into commercially provided 60-cycle, 110-120 volt power grids commonly in use throughout the country (and equally well convertible into other common standards in use throughout the world).
Of course, the xe2x80x9cpower netxe2x80x9d can also perfectly well supply other standards of electrical power supply, such as 12-volt DC or other storage battery requirements.
A further attribute of the xe2x80x9cpower netxe2x80x9d is that an optional modification thereto may be utilized directly to convert ocean water to fresh water using reverse osmosis or other suitable means.
A multiplicity of the pressure collection/chamber devices of the xe2x80x9cpower netxe2x80x9d modules may be linked via pressure hoses so that large volumes of water under suitable regulated pressure may be collected together to operate a bank of generators (of same or different capacity), so that the most efficient number or size of generators may be engaged at any given moment to optimize power output.
The ability to compound the number of the various components of the xe2x80x9cpower netxe2x80x9d into modular applications allows great design flexibility, permits rotational maintenance programs without taking the entire system out of operation, and accommodates add-on capacity.
The elegant simplicity of the several preferred embodiments of the invention permits the greatest possible utilization of existing commercially-available components, rendering the invention affordable. It is the unique compounding of the elements of the xe2x80x9cpower netxe2x80x9d that comprises the invention.
Further attributes of the invention are elucidated within the description below.